Cauda equina neurinoma associated with normal pressure hydrocephalus--case report.

A 45-year-old male was hospitalized because of gait disturbance, urinary incontinence, and memory disturbance. A computed tomographic (CT) scan revealed dilatation of the cerebral ventricles, and a metrizamide CT scan showed reflux into all ventricles. Cerebrospinal fluid obtained at the time of metrizamide CT was highly xanthochromic. Myelograms demonstrated a tumor between the inferior portion of the fifth lumbar vertebra and that of the second sacral vertebra. After removal of a spinal tumor involving nerve fibers at the cauda equina, his symptoms disappeared and the spinal fluid protein normalized. Three months after surgery, a CT scan revealed reduction of cerebral ventricular size. There are 10 reported cases of spinal tumors resulting in normal pressure hydrocephalus. All these and present cases involved protein in the spinal fluid, which might have been the cause of the hydrocephalus.